Driving my Formula yesterday around town with the AC on. Temp stayed right on 210, then climbed to about 220 in a little stop and go traffic. Got home and was still running the a.c. for maybe five minutes or so and the engine overheated. Pegged the temp gauge. Shut her off and observed boiling fluid coming out of the radiator cap. Let her cool off overnight and checked fluid level. Radiator full and the reservoir dipstick clearly showed full/cold. Possible cap issue? Brand new AC Delco water pump and thermostat and all new radiator hoses installed about 6 weeks ago.